/*
 * Copyright (c) 2013, SRI International
 * All rights reserved.
 * Licensed under the The BSD 3-Clause License;
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 * 
 * http://opensource.org/licenses/BSD-3-Clause
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 
 * Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * 
 * Neither the name of the aic-web-praise nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
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package com.sri.ai.lpitools.gwtgui.client.components.manager;

import java.util.ArrayList;
import java.util.List;

import com.google.gwt.user.client.rpc.AsyncCallback;
import com.sri.ai.lpitools.cobra.gwtutil.dataobjects.shared.UserInfo;
import com.sri.ai.lpitools.gwtgui.client.RPCService;
import com.sri.ai.lpitools.gwtgui.client.components.dialogs.MessageDialog;
import com.sri.ai.lpitools.gwtgui.client.util.JSONUtil;

/**
 * Manager class which holds information regarding the currently logged in User
 * @author bellwein
 */
public class UserManager {

	private UserInfo currentUser;
	
	private List<UserListener> userListeners;
	
	public UserManager() {
		userListeners = new ArrayList<UserListener>();
	}
	
	public void setUser(final String user){
		
		RPCService.Util.getInstance().checkUser(user, new AsyncCallback<String>(){

			@Override
			public void onFailure(Throwable caught) {
				//TODO show some sort of error message, or indicate with a code comment why this isn't necessary
			}

			@Override
			public void onSuccess(String resultString) {
				if (!resultString.equalsIgnoreCase(RPCService.invalidReturnString)) {
					//ensure that we notify any interested listeners
					UserInfo userInfo = JSONUtil.getUserInfo(resultString);
					currentUser = userInfo;
				} else {
					MessageDialog.showMessageDialog("Not a valid User");
					currentUser = null;
				}	
				notifyListenersUserChanged();
			}
		});
	}

	public boolean isUserLoggedIn() {
		return getCurrentUser() != null;
	}
	
	public UserInfo getCurrentUser() {
		return currentUser;
	}
	
	protected void notifyListenersUserChanged() {
		UserInfo user = getCurrentUser();
		for (int i= userListeners.size()-1; i >= 0;i--) {
			userListeners.get(i).loggedInUserChanged(user);
		}
	}
	
	public boolean addUserListener(UserListener userListener) {
		return this.userListeners.add(userListener);
	}
	
	public boolean removeUserListener(UserListener userListener) {
		return this.userListeners.remove(userListener);
	}

	public void setLogIn(UserInfo userInfo) {
		currentUser = userInfo;
		notifyListenersUserChanged();		
	}
}
